1. Technical Field
This document relates to methods and materials involved in treating cancer. For example, this document provides methods and materials for identifying a mammal as having an elevated level of CD8 T cells that express PD-1 and CD11a polypeptides (PD-1+/CD11ahigh CD8 T cells) and administering a PD-1 inhibitor to such a mammal.
2. Background Information
CD11a (LFA-1, lymphocyte functional-associated antigen 1) is a polypeptide expressed by T cells. It binds to ICAM-1 on antigen-presenting cells and functions as an adhesion molecule. CD11a is indispensable in mediating conjugation of cytotoxic T lymphocytes (CTLs) and target cells. Blocking CD11a can dramatically reduce the killing of tumor cells and rejecting of transplants by CTLs.
B7-H1 is a polypeptide expressed by a variety of tumor cells. It also is constitutively expressed by macrophages and dendritic cells, its expression being up-regulated upon cell activation. PD-1 is a receptor for B7-H1 polypeptides.